diff options
| author | Even Xu <even.xu@intel.com> | 2025-05-14 14:19:40 +0800 |
|---|---|---|
| committer | Jiri Kosina <jkosina@suse.com> | 2025-06-10 21:15:58 +0200 |
| commit | 45e92a093099eaf71ff2915a5f6ab5c04c8385e6 (patch) | |
| tree | ac136e9f333d3c30d07555294cc106706a5892cb /Documentation/hid | |
| parent | 13dd60947f439bc2e7a37ed14fbec6b6ff591572 (diff) | |
HID: Intel-thc-hid: Intel-thc: Introduce max input size control
This patch adds support for a new feature, named "Max Input Size
Control", allowing driver to set a maximum input size for RxDMA. This
enhancement aims to prevent RxDMA buffer overruns caused by data
corruption on the I2C bus, thereby improving overall system stability.
APIs added:
- thc_i2c_set_rx_max_size(): Set the maximum input size for I2C RxDMA.
- thc_i2c_rx_max_size_enable(): Enable or disable the max input size
control.
As this max input size control feature is only applicable to RxDMA
and must remain disabled during SWDMA operations, it also involves
a change in SWDMA code to record the max input size control feature
state before SWDMA and restore the state after SWDMA.
Signed-off-by: Even Xu <even.xu@intel.com>
Tested-by: Chong Han <chong.han@intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Jiri Kosina <jkosina@suse.com>
Diffstat (limited to 'Documentation/hid')
| -rw-r--r-- | Documentation/hid/intel-thc-hid.rst | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/Documentation/hid/intel-thc-hid.rst b/Documentation/hid/intel-thc-hid.rst index dc9250787fc5..15b04fa215c7 100644 --- a/Documentation/hid/intel-thc-hid.rst +++ b/Documentation/hid/intel-thc-hid.rst @@ -188,6 +188,20 @@ Control register. Reset line is controlled by BIOS (or EFI) through ACPI _RST method, driver needs to call this device ACPI _RST method to reset touch IC during initialization. +2.3 Max input size control +-------------------------- + +This is a new feature introduced in Panther Lake platform, THC hardware allows driver to set +a max input size for RxDMA. After this max size gets set and enabled, for every input report +packet reading, THC hardware sequencer will first read incoming input packet size, then compare +input packet size with the given max size: +- if input packet size <= max size, THC continues using input packet size to finish the reading +- if input packet size > max size, there is potential input data crash risk during + transferring, THC will use max size instead of input packet size for reading + +This feature is used to avoid data corruption which will cause RxDMA buffer overrun issue for +I2C bus, and enhance whole system stability. + 3. High level concept ===================== |